1. Field of the Invention
The present invention relates to a control method of an audio/video system, especially a method for making audio/video devices, which are not the input source of a display device, automatically entering into standby state so as to save power.
2. Description of the Prior Art
The high definition multimedia interface (HDMI) is widely used as a transmission interface of TVs, displays, notebooks and tablets due to the HDMI being capable of transmitting uncompressed high definition video data and multichannel audio data. The set-top box, video game console, Blu-ray player or other peripheral devices with the audio/video (A/V) processing functions generally have an HDMI port which can transmit processed A/V data or multimedia data to a display device for displaying images, thus increasing the functions of the system and allowing the user to more conveniently view multimedia images. For example, the user may view multimedia data other than programs of TV channels through connecting a multimedia set-top box to the display. When the user is controlling the multimedia set-top box, the multimedia set-top box will generate an on-screen display (OSD) menu displayed on the TV and the user can use a remote control to control the set-top box.
However, if the user wants to control the TV and the multimedia set-top box at the same time, the user has to use two remote controls corresponding to the set-top box and TV respectively. This could be very inconvenient to operate. Besides, the image of the multimedia set-top box's user interface must be firstly generated by the multimedia set-top box and then transmitted to the display device for displaying. If the TV of a multimedia system incorporates the control function of the set-top box so the user can use the remote control of the TV to control the set-top box, the control signal to the set-top box will be transmitted from the TV to the set-top box when the user controls the set-top box, and then the set-top box will generate image of the user interface after processing the control signals. After the image of user interface is transmitted to the TV, and the TV can display the result corresponding to the control signal accordingly. In this way, a period of time is required for transmitting the control signal and images, thus delaying the result of the user's control operations to the set-top box. Under this situation, the multimedia system can not provide real-time operations to the user.
In addition, the display devices of prior art usually include multiple signal input ports, e.g. the video graphics array (VGA), digital visual interface (DVI) and HDMI ports, for coupling to multiple A/V peripheral devices, e.g. personal computers, notebooks and multimedia set-top boxes. However, when a specific input port of a display device is selected as the signal source, the A/V devices corresponding to the unselected input ports will remain in current state instead of entering standby state automatically, thus increasing the overall power consumption. Moreover, it is very inconvenient for the user to manually turn off the peripheral devices corresponding to the unselected input ports one by one.